1. Field of the Invention
The present invention relates to pipe couplings. More particularly, the present invention relates to a female coupling member suitable for handling high-pressure fluid, e.g. hydrogen gas, and also relates to a pipe coupling having the female coupling member.
2. Description of Related Art
Vehicles equipped with a fuel cell using hydrogen gas as a power source have been put to practical use. Such fuel cell vehicles need to be supplied with hydrogen gas at a hydrogen gas supply station similar to a gasoline filling station for general gasoline engine vehicles. In this case, a female coupling member attached to the outlet of a hose for discharging and supplying hydrogen gas from a hydrogen gas storage tank at the hydrogen gas supply station is connected to a male coupling member attached to the inlet of a hydrogen gas storage tank in the vehicle, thereby supplying hydrogen gas to the vehicle.
Hydrogen gas supplied from the hydrogen gas storage tank to the vehicle is generally at a pressure of the order of 70 MPa. Therefore, all possible measures need to be taken to prevent the occurrence of an accident such as leakage of hydrogen from the pipe coupling comprising the male and female coupling members. US2011/0037254A1 and U.S. Pat. No. 8,186,649B2 disclose a female coupling member that is allowed to connect with a male coupling member only when the female coupling member is not in fluid communication with a hydrogen gas source, and that is allowed to pass high-pressure hydrogen gas only when the male coupling member is completely connected to the female coupling member. Further, the female coupling member is configured to prevent accidental disconnection of the male coupling member from the female coupling member by the operator when hydrogen gas is being supplied with the associated valve member placed in an open position.